These Sample papers are part of CBSE Sample Papers for Class 10 Science. Here we have given CBSE Sample Papers for Class 10 Science Paper 1.
CBSE Sample Papers for Class 10 Science Paper 1
Board | CBSE |
Class | X |
Subject | Science |
Sample Paper Set | Paper 1 |
Category | CBSE Sample Papers |
Students who are going to appear for CBSE Class 10 Examinations are advised to practice the CBSE sample papers given here which is designed as per the latest Syllabus and marking scheme as prescribed by the CBSE is given here. Paper 1 of Solved CBSE Sample Paper for Class 10 Science is given below with free PDF download solutions.
Time Allowed: 3 hours
Max. Marks: 80
General Instructions:
- The question paper comprises two sections, A and B. You are to attempt both the sections.
- All questions are compulsory.
- All questions of Section-A and B are to be attempted separately.
- There is an internal choice in three questions of three marks each, two questions of five marks each and one question (for assessing the practical skills) of two marks.
- Question numbers 1 and 2 in Section-A are one mark question. They are to be answered in one word or in one sentence.
- Question numbers 3 to 5 in Section- A are two marks questions. These are to be answered in 30 words each.
- Question numbers 6 to 15 in Section-A are three marks questions. These are to be answered in about 50 words each.
- Question numbers 16 to 21 in Section-d are five marks questions. These are to be answered in 70 words each.
- Question numbers 22 to 27 in Section- B are based on practical skills. Each question is a two marks question. These are to be answered in brief.
SECTION-A
Question 1.
Name the green dot-like structures in some cells observed by a student when a leaf peel was viewed under a microscope. What is this green colour due to?
Question 2.
In a germinating seed, which parts are known as future shoot and future root? Mention the function of cotyledon.
Question 3.
How many groups and periods are there in the Modern Periodic Table? How do the atomic size and metallic character of elements vary as we move:
- down a group and
- from left to right in a period
Question 4.
In the figure given below a narrow beam of white light is shown to pass through a triangular glass prism. After passing through the prism, it produces a spectrum XY on a screen.
- State the colour seen at X and Y.
- Why do different colours of white light bend through different angles with respect to the incident beam of light?
Question 5.
Mention any four limitations in harnessing wind energy on a large scale.
Question 6.
No chemical reaction takes place when granules of a solid, A are mixed with the powder of another solid, B. However when the mixture is heated, a reaction takes place between its components. One of the products, C is a metal and settles down in the molten state while the other product, D’floats over it. It was observed that the reaction is highly exothermic.
- Based on the given information make an assumption about A and B and write a chemical equation for the chemical reaction indicating the conditions of reaction, physical state of reactants and products and thermal status of reaction.
- Mention any two types of reactions under which above chemical reaction can be classified.
Question 7.
What happens when dilute hydrochloric acid is added to the following and write balanced chemical equations:
- Bleaching powder
- Zinc granules
- Baking soda
OR
You have two solutions A and B. The pH of the solution A is 6 and pH of solution B is 8. Which solution has more hydrogen ion concentration? Which of these is acidic and which one is basic?
Question 8.
Atoms of eight elements A, B, C, D, E, F, G and H have the same number of electronic shells but different number of electrons in their outermost shell. It was found that elements A and G combine to form an ionic compound. This compound is added in a small amount to almost all vegetable dishes during cooking. Oxides of elements A and B are basic in nature while those of E and F are acidic. The oxide of D is almost neutral. Based on the above information answer the following questions:
- To which group or period of the periodic table do the listed elements belong?
- What would be the nature of compound formed by a combination of elements B and F?
- Which two of these elements could definitely be metals?
- Which one of the eight elements is most likely to be found in gaseous state at room temperature?
- If the number of electrons in the outermost shell of elements C and G be 3 and 7 respectively, write the formula of the compound formed by the combination of C and G.
Question 9.
- Explain why the rate of photosynthesis in plants is low both at lower and higher temperatures.
- Is green light most or least useful in photosynthesis and why?
OR
Why does absorption of digested food occur mainly in the small intestine?
Question 10.
Mayank’s father never bothered to check the brand/or contents of the salt he had purchased from the market. Mayank noticed that her sister had developed swollen neck. The doctor advised her to eat iodised salt.
- Name the disease from which Mayank’s sister suffered.
- Why has the doctor advised her to eat iodised salt?
- How will this incidence influence Mayank’s attitude towards health?
Question 11.
How did Mendel explain that it is possible that a trait is inherited but not expressed in an organism?
Question 12.
“Evolution and classification of organisms are interlinked.” Give reasons to justify this statement.
Question 13.
At what distance should an object be placed from a convex lens of focal length 18 cm to obtain an image at 24 cm from it on the other side. What will be the magnification product in this case?
Question 14.
Given that R1 = 10Ω, R2 = 40Ω, R3 = 30Ω, R4 = 20Ω and RA is the parallel combination of R1 and R2 whereas RB is the parallel combination of R3 and R4. Combination RA is connected to the positive terminal of 12 V battery while combination RB is connected to the negative terminal. Ammeter A is connected between the resistors RA and RB.
- Find RA and RB. Also calculate total resistance in the circuit.
- Draw the circuit diagram showing above combinations connected to battery and ammeter.
Question 15.
State the rule to determine the direction of a
- magnetic field produced around a straight conductor-carrying current
- force experienced by a current-carrying straight conductor placed in a magnetic field which is perpendicular to it and
- current induced in a coil due to its rotation in a magnetic field.
OR
What is the role of fuse used in series with any electrical appliance? Why should a fuse with defined rating not be replaced by one with a larger rating?
Question 16.
Write the names and symbols of two most reactive metals belonging to group I of the periodic table. Explain by drawing electronic structure how either one of the two metals reacts with a halogen. With which name is the bond formed between these elements known and what is the class of the compound so formed known? State any four physical properties of such compounds.
Question 17.
Why are certain compounds called hydrocarbons? Write the general formula for homologous series of alkynes, alkynes and alkynes and also draw the structure of the first member of each series. Write the name of the reaction that converts alkynes into alkynes and also write a chemical equation to show the necessary conditions for the reaction to occur.
Question 18.
-
- Which part of the nervous system controls reflex arcs?
- With the help of a diagram trace the sequence of events, which occur when we touch a hot object.
- Mention the part of the neuron that acquires information and the form in which information travels.
- Name the hormone synthesised at the shoot tips. How does it help the plant to response to light?
OR
- What causes tendril to encircle or coil around the object in contact with it? Explain the process involved.
- What is chemotropism? Give one example.
Question 19.
- A student suffering from myopia is not able to see distinctly the objects placed beyond 5 m. List two possible reasons due to which this defect of vision may have arisen. With the help of ray diagrams, explain
- why the student is unable to see distinctly the objects placed beyond 5 m from his eyes.
- the type of the corrective lens used to restore proper vision and how this defect is corrected by the use of this lens. .
- If, in this case, the numerical value of the focal length of the corrective lens is 5 m, find the power of the lens as per the new Cartesian sign convention.
Question 20.
- Draw the pattern of magnetic field lines through and around a current carrying solenoid. What does the magnetic field pattern inside the solenoid indicate?
- How can this principle be utilised to make an electromagnet?
- State two ways by which strength of this electromagnet can be increased.
OR
Explain the underlying principle and working of an electric generator by drawing a labelled diagram. What is the function of brushes?
Question 21.
-
- Water is an elixir of life, a very important natural resource. Your Science teacher wants you to prepare a plan for a formative assessment activity, “How to save water, the vital natural resource”. Write any two ways that you will suggest to bring awareness in your neighbourhood, on ‘how to save water’.
- Name and explain any one way by which the underground water table does not go down further.
- Explain two main advantages associated with water harvesting at the community level.
SECTION-B
Question 22.
A student dips pH papers in solutions A and B and observes that the pH paper turns blue and orange respectively in them. What does he infer?
OR
A student took the following samples to find out their pH using pH paper: dilute hydrochloric acid, lemon juice, washing soda and soap solution. The teacher remarked that one of the samples taken was not proper. To which sample was the teacher referring to?
Question 23.
When asked to set up an experiment to show that ‘light is necessary for photosynthesis’, a student ran to the school garden and set up the experiment using a plant growing in the school garden. The experiment failed. His fellow student made the following suggestions to get success.
Student A: Safranin should be used instead of iodine.
Student B: The leaf should not be boiled in alcohol to remove chlorophyll before testing for starch.
Student C: Transparent paper strip should be used instead of black paper strip.
Student D: The plant should be de-starched before starting the experiment. Which student made the right suggestion?
Question 24.
What will happen if a student while studying the dependence of current on the potential difference keeps the circuit closed for a long time to measure the current and potential difference?
Question 25.
Mention the essential material (chemicals) to prepare soap in the laboratory. Describe in brief the test of determining the nature (acidic/alkaline) of the reaction mixture of saponification reaction.
Question 26.
Draw in sequence (showing the four stages), the process of binary fission in Amoeba.
Question 27.
A beam of white light falling on a glass prism gets split up into seven colours marked 1 to 7 as shown in the diagram.
A student makes the following statements about the spectrum observed on the screen.
- The colours at positions marked 3 and 5 are similar to the colour of the sky and the colour of gold metal respectively. Is the above statement made by the student correct or incorrect? Justify.
- Which two positions correspond closely to the colour of
- brinjal,
- ‘danger’ or stop signal lights?
Answers
SECTION-A
Answer 1.
Chloroplast, chlorophyll
Answer 2.
In a germinating seed, plumule in known as future shoot and radicle is known as future root.
The function of cotyledon is to store food for the future plant or embryo.
Answer 3.
There are 18 groups and 7 periods in the Modern Periodic Table.
- • Atomic size increases
• Metallic character increases - • Atomic size decreases
• Metallic character decreases
Answer 4.
- X – Violet
Y – Red - This happens due to the following reasons:
- Due to difference in speed of different colours
- Due to difference in wavelength and frequency
- Due to refractive index of glass is different for different colours of light.
Answer 5.
- It can be used only at those places where wind blows for the greater part of the year.
- Wind speed should be higher than 15 km h to rotate the turbine at the required speed.
- Need of a back up facility when there is no wind.
- Requires large area for setting up wind energy farms.
- Tower and blades require a high level of maintenance. (Any four)
Answer 6.
A: Fe2O3, B : A1
(ii) Displacement Reaction Redox Reaction Exothermic Reaction (Any two)
Answer 7.
1. Calcium chloride and chlorine gas are formed.
2. Hydrogen gas is evolved.
3. Sodium chloride and carbon dioxide gas are formed.
OR
The pH of a solution is inversely proportional to its hydrogen ion concentration. This means that the solution having lower pH will have more hydrogen ion concentration. Thus, solution A will have more hydrogen ion concentration.
A solution with pH < 7 is acidic. Hence, solution A is acidic.
A solution with pH > 7 is basic. Hence, solution B is basic.
Answer 8.
- Third Period or Group – 1, 2, 13, 14, 15, 16, 17, 18 respectively.
- Ionic or Electrovalent
- A and B
- G or H
- CG3
Answer 9.
- Photosynthesis is an enzymatic process. The enzymes function within an optimum range of temperature which is neither very low nor very high. At low temperature the activity of enzymes is lowered due to which the rate of photosynthesis is also low. Again when the temperature is very high, the activity of enzymes decreases which leads to low rate of photosynthesis.
- Green light is least useful in photosynthesis, because chlorophyll does not absorb green light.
OR
Maximum absorption occurs in small intestine because
- digestion is completed in small intestine.
- inner lining of small intestine is provided with villi which increases the surface area for absorption.
- wall of intestine is richly supplied with blood vessels (which take the absorbed food to each and every cell of the body):
Answer 10.
- She may be suffering from Goitre/Thyroid related disease.
- Iodine present in iodised salt is needed to produce thyroxin hormone.
- Mayank would become more careful regarding health, will be conscious of his diet and of people around him.
Answer 11.
- In Mendel’s experiment, when pure tall pea plants were crossed with pure dwarf pea plants, only tall pea plants were obtained in F1 generation.
- On selfing the pea plants of F, generation both tall and dwarf pea plants were obtained in F2 generation.
- Reappearance of the dwarf pea plants in F2 generation proves that the dwarf trait was inherited but not expressed in F1 generation.
Answer 12.
Evolution and classification of organisms are interlinked because of following reasons.
- Different life forms have evolved during the course of evolution. Classification deals with the grouping of these life forms into groups and sub groups based on similarities and differences.
- The more characteristics any two species have in common, more closely they are related.
Thus, classification helps in tracing the evolutionary relationship between the two organisms. Hence, evolution and classification are interlinked.
Answer
Answer 15.
- The direction of magnetic field produced around a current-carrying conductor is given by right hand thumb rule. If the conductor carrying current is held in the right hand in such a way that the thumb points in the direction of current, then direction of curl of fingers gives the direction of the magnetic field.
- The direction of force experienced by a straight conductor carrying current placed in a magnetic field, which is perpendicular to it is determined by Fleming’s left hand rule. Hold the thumb and first two fingers of the left hand at right angles to each other with the first finger pointing in the direction of the field and the second finger in the direction of the current, then the thumb points in the direction of the motion.
- The direction of current induced in a circuit by changing magnetic flux due to motion of a magnet is determined by Fleming’s right hand rule. If we stretch our right hand in such a way that the thumb, forefinger and central finger remain perpendicular to each other, so that the forefinger indicates the direction of the magnetic field and the thumb in the direction of motion of conductor; then the central finger indicates the direction of induced current.
OR
Fuse is used for protecting appliances due to short-circuiting or overloading. The fuse is rated for a certain maximum current and blows off when a current more than the rated value flows through it. If a fuse is replaced by one with larger ratings, the appliances may get damaged while the protecting fuse does not burn off. This practice of using fuse of improper rating should always be avoided.
Answer 16.
Sodium/Na, Potassium/K, Rubidium Rb, Cesium/Cs
The bond formed between two elements is ionic or electrovalent bond and the class of compound is salts/ionic compounds. Physical properties:
- Crystalline solid at room temperature
- Brittle, hard solid
- Soluble in water
- Have high melting and boiling point
- Conduct electricity in aqueous or molten form
Answer 17.
Compounds of hydrogen and carbon are called hydrocarbons.
Answer 18.
1. (a) Spinal cord
2. Auxin When light is coming from one side of the plant auxin diffuses towards shady sides. This concentration stimulates the cells to grow longer’on the side of the shoot which is away from the light and shoot bends.
OR
- Auxin diffuses to the other part which is away from the support. Part of the tendril in contact from the support does not grow rapidly. Part of the tendril away from the support grow rapidly and cause the tendril to grow around a support.
- Chemotropism—Movement in plant due to chemicals as stimulus. Example: Growth of pollen tubes towards ovules (or any other).
Answer 19.
- The defect may have arisen due to following reasons: excessive curvature of the eye lens elongation of the eyeball
- Because the image of the object is formed in front of the retina and not on it.<
- Concave or diverging lens is used to restore proper vision. It will bring the image back on the retina.<
- f = -5 m (since lens is concave)
In case of myopia,
\(p=\frac { 1 }{ f\left( metre \right) } =\frac { 1 }{ -5 }\)
P= -0.2 D
Answer 20.
1.
Magnetic field pattern inside the solenoid indicates that the magnetic field is same at all points inside the solenoid.
2. This principle is utilised to magnetise a piece of magnetic material like soft iron when placed inside the coil.
3. Ways to strengthen this electromagnet:
- (a) Increase the amount of electric current through it.
- (b) Increase the number of turns of coil.
OR
An electric generator converts mechanical energy into electrical energy. Alternating current generators or AC generators produce alternating current.
Principle: It works on the principle of electromagnetic induction. Whenever the magnetic flux through a coil changes. induced current is produced.
Construction : Alternating current generator consists of a rectangular coil ABCD called armature. The armature coil consists of large number of turns of insulated copper wire wound over a soft iron core. The coil is kept between the poles of a strong magnet. In the figure shown R, and R, are two slip rings connected to the two ends of the coil and convey the current produced to outside circuit. B, and B., are two carbon brushes remain in sliding contact with slip rings.
Working : The coil of the generator is rotated with the help of an axel. When coil rotates, it cuts the magnetic lines of force (magnetic field) near the north W) and south (S) poles of the magnet. By electromagnetic induction, a current is induced in the coil. The direction of this current is given by Fleming’s right hand rule. As this coil turns clockwise, arm AB G – moves up and arm CD goes down. The direction of current is from A Basic principle of operation of AC generators. to B in 1B and C to D in CD. The induced current is taken out through slip rings and carbon brushes. Ifier half this rotation, AB and CD interchange their position. Now CD-moves upward and AB downward.
The direction of induced current is from D to C in CD and B to A in AB, during this half rotation. The slip rings R, and R, also rotate along with the coil ABCD. Thus, their polarities keep changing after every half rotation. Thus, the current changes its direction twice in one complete revolution of the coil. Such a current which changes its polarity after fixed intervals is called alternating current.
Function of Brushes: The brushes B, and B, remain fixed in their positions and maintain sliding contacts with the rotatable slip rings R, and R, respectively. It is through these brushes that the current induced in the
armature coil is fed to the external circuit by means of line wires.
Answer 21.
1. (a) Two ways of creating awareness are:
- Door to door campaigning.
- Nukkad natak/any other methods
(b) Rain water harvesting: It is one of the most efficient method for recharging the underwater table. It is a process by which rain water is collected and stored to ensure recharging of aquifers. It can further be used for agriculture and irrigation. By this, we can reduce our dependence on storage dams. There are generally two ways of rainwater harvesting: Surface run
off harvesting and roof top rain water harvesting.
2. Following are the advantages of water harvesting at the community level:
- Water stored during rainy season can be used as and when required by the community.
- Ground water level increases due to recharging.
SECTION-B
Answer 22.
He infers that A is sodium carbonate solution and B is acetic acid. The pH paper turns blue when dipped in solution A, it means A is a strong base having pH 9 and the pH paper turns orange when dipped in solution B, it means B is a strong acid having pH+.
OR
The teacher was referring to washing soda because it is in powder formi not in liquid form. To find pH using pH paper, the sample should be in liquid form.
Answer 23.
Student D made the right suggestion because destarching of the leaf by keeping the plant in darkness before starting the experiment is essential.
Answer 24.
If the circuit is kept closed for a long time t resistor will get heated up and its value will change. This is because heat produced in any resistor, H = I2 Rt As time will increase heat produced will increase. Hence resistor will get heated up due to which its value will change.
Answer 25.
Vegetable oil sodium hydroxide:
Test: Soaps are basic in nature we can do litmus test to determine the nature of saponification mixture. Red litmus will turn to blue.
Answer 26.
Answer 27.
- The statement made by the student is incorrect. Positions marked 3 (yellow) and 5 (blue) are similar to the colour of gold metal and the colour of the sky respectively. The student is stating the nature of colours in reverse order.
- The position marked 7 (violet) corresponds closely to the colour of a brinjal.
- The position marked 1 (red) corresponds closely to the colour of ‘danger’ or stop signal lights.
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